Foil filming machine



Nov. 19, 1940. G. w. ELsEY FOIL FILMING MACHINE Filed May 14, 1956 7Sheets-Sheet 1 :NVE T R "E j W1 @ATTORNEY/,

Nov. 19, 1940.

G. W. ELSEY FOIL FILMING MACHINE Filed May 14, 1936' 7 Sheets-Sheet 2.www EN SMN gn lNvENToR BBM.

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Nov. 19, 1940. G. w. ELSEY 2,222,195

-FoIL lzvILMINGl MACHINE Filed May 14, 1956 '7 Sheets- Sheet I5 wATTORNEY@ Nov. 19, 1940. G, w ELSEY 2,222,195

F011. FILMING MACHINE Filed May 14, 1936 7 sheets-Sheet 4 am .ma 5" sSQM; 721%?,

' Sheets-Sheet 6` ATTORNEY-v Nov. 19,I 1940. G. w. ELsEY FOIL FILMINGMACHINE Filbd May 14, 1936 Nav. 1.9r 1940.v G. w1 ELsr-:Y 2,222,195

Pom mmm@ MACHINE Filed May' 14, 1936 7 Sheets-Sheet 7 ATToRNi-iwPatented Nov. 19, 1940 PATENT OFFICE Fon. FILMING MACHINE George W.Elsey, Dayton, Ohio, assignor to General Motors Corporation, Detroit,Mich., a corporation of Delaware Application May 14, 1936, Serial No.79,805

5' claims. l (o1. 264-5) This invention relates to an apparatus forforming a dielectric film upon a metal foil for the purpose of makingelements suitable for electrolytic condensers or similar apparatus using5 filmed electrodes. In the formation of dielectric iilm` such asaluminum foil, the foil `is passed through a lming bath containing asuitable electrolyte. An electriccurrent is passed through this bathbetweenthe lm as the anode and a l suitable cathode.

The chief aim and object of the present in- Vention is to form upon thefilm forming metal foil a dielectric lm which will have a high degree4of uniformity with respect to its operation in l electrolytic devices,and to reduce the time required to form` such a film thereby reducingthe cost of manufacture-of apparatus using lmed electrodes. f f

In view to accomplishing these general objects,

20 the present invention provides means for maintaining the electrolyticfilming bath as uniform as possible with respect to its temperature andconsistency. The temperature of the bath is regulated within properlimits, preferably around 180 F., and is constantly maintained incirculation so Athat the bath will be uniform at the variout levels ofthe filming tank. Means are provided for rapidly disspating excessiveheat from `410 feed lubrication which constantly circulates lubricatingoil to and from these bearings. The bearing cavities are kept filledwith oil so as to prevent fumes from the electrolyte contacting with thebearings and causing them .to corrode. These 45 features enable theapparatus to operate very smoothly and uniformly, the friction to beovercome while the spindles and rolls revolve at a certain rate of speedbeing uniform to a high degree. VBy the use ofsuch apparatus vthe foil59 may be fed atea relativelyA high rate of speed through the lming bathwithout danger of tearing the foil.

A further object of the invention is to facilitate the threading of thelm around the guide rolls,

55 between the feed rolls of the machine and between the guides whichhold the lm uniformly spaced with respect to the electrodes.

A still further "object is to provide for the facile removal andreplacement of electrodes.

A further object is to provide for a stopping of the machineautomatically in case the lm breaks.

A further object is to provide for easy splicing of the film from themachine.

A further object is to provide for the alignment of the foil take-upspindle With the foil as it passes from the feed rolls.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred embodiment of the present invention isclearly shown.

Fig. 1 is a diagram of a lming machine.

Fig. 2'is a fragmentary side elevation of the machine.

Fig. 3 is a top plan view.

Fig. 4 is a perspective view of a portionof the machine looking in thegeneral direction of arrow llof Fig. 3.

Fig.-5 is a perspective view taken in the direction of the arrow '5 ofFig. 3.

Fig. 6 is a vertical sectional view of the agitator tank.

Fig. 'l is a perspective View of the device for guiding the film as itpasses through the lming I tank.

.Q'Fig. 8 is a fragmentary perspective view taken in the direction ofthe ar ow 8 of Fig. 7. L

Fig. Sis a perspective View of part 36|. Fig. l() is a sectional viewthereof taken on line IIL-I0 of Fig."7. i

Figs. l1 and 12 are' sectional views taken respectively on lines lllland l2-I2 of Fig. 2.

Referring to the diagrammatic illustration of the machine shown in Fig.1, the supply roll of foil to be filmed is designatedby A. The reel A isrotatably supported. The foil strip, designated by lF,.passes around arotatably supported cylinv der or drur'n B, then around a roller C, then'vertically downward and around the roller D,

` electrodes L connected to a common lead wire M.

The electrolytic circuit within the tank K is completedthrough the foilitself. The 'roller B over which the foil passes is metallic and is inelectrical connection with a metallic flange N, the lower edge of whichis immersed in a bath of mercury P into which an electrode Q isconnected with lead wire R. The film is caused to pass through thefilming tank K at a predetermined uniform speed, preferably 36 feet perminute. The foil is maintained at all times at a predetermined distancefrom the electrodes L. 4The electrolyte within the tank K is maintainedat a definite temperature and at a definite chemical analysis and isalso constantly stirred to maintain it as a homogeneous mixture orsolution. In this way a film having great uniformity is deposited on thefoil.

The machine which has been described diagrammatically will now bedescribed structurally with reference to Figs. 2 to 4 inclusive. Themechanism is supported bya frame 20 resting upon a base or pedestal 2|.The frame 29, at its left handA end, carries bracket 22 which is in theform of a box having its side closed by a non-conducting plate 23. InIthe space between the plate 23 and a side wall of the bracket 22 thereis located a non-conducting vessel 24 for containing the mercury bath P-into which the electrode Q extends. The space within the bracket 22also receives the conducting ange N which is silver soldered to themetallic roller B, which in turn is supported byy non-conducting,preferably rubberv roller 25 which is rotatably supported byantifriction bearings to be described on a stub shaft 26 carried byabracket 21 attached to the frame 20. The friction produced by the'flange N passing through the mercury bath P is relatively slight.

The bracket 21 carries ball bearings 28 rotatably supporting a shaft 29carrying a xed flange 3D of non-conducting material such as hard rubber.The ange 30 has a hub 3| which insulates the flange 30 from the' shaft29. rIhe hub 3| iscovered by a metal ring 32 having a conical surface 33for engaging one end of the core AI which supports the supply reel A ofunfilmed foil.- 34 is a nut which screw threadedly engages the righthand end of the shaft 29. The nut 34 has a hub which is surrounded byinsulation 35 which in turn supports a metal ring 36 having a conicalsurface 31 for engaging the other end of the supply roll 'A. A lightfriction drag or braking action is placed upon the shaft 29 by means offriction discs 4|) and 4I, the former being stationary and the latterbeing connected to the shaft by a coupling 42. The disc 40 ispreventedfrom rotating by a pin 43 attached to a cover'plate 44 inthe recess 45within which the shaft 29 is located. Pressure is applied to the disc 40by one or more springs 46 located between the disc 40 and an adjustingdisc 41 which is guided by the pin 43 and also held from rotating. Thedisc 41 may be moved toward the disc 40 by a screw 48 held in adjustedposition by lock nut 49. When the screw 48 is loosened the spring 46will move the disc 41 from the disc 40. Plate 44 is provided withopenings for re- 75 ceivingconnections with a lubricating oil supplyline 50 and a return line 5| so that the chamber 45 may be supplied withoil. The leakage of oil is prevented by the packing 52.

In order that the foil F will be maintained in good electrical contactwith the conducting roll B a strap 6U ofl soft leatherl or othersuitable material is held in engagement with a portion of the foil Fwhich goes around roll B. This strap 6l) is held by hook 6| secured by abracket 62 which ispivotally attached at 63 to the frame y2|). Counterclockwise rotation'of the bracket 62 is resisted by coil spring 64 shownin Fig. 4. The lower end of the strap is connected to a rod 65 carryingone Vor more weights 66. The mass of the weights 66 should be such as tocause the foil F to bear against the roll B with pressure suiiicient forgood electrical engagement but not to produce excessive friction uponthe foil. When threading the foil upon the machine, the arm 62 is turnedcounterclockwise as viewed in Figs. 2 and 4 so that the strap 60 willhang free of the roll B.

Roller C is shown in detail in Fig. 12. Roller C is of non-conductingmaterial, preferably rubber, and is mounted upon a metal sleeve 10journalled by ball bearings 1| upon a stub shaft 12 carried by bracket13 attached' to the frame 20. The shaft is provided with passages 14 and15 for the inlet and outlet of lubricant circulated through pipes 16,Aand 11 attached by suitable couplings to the shaft 12. The oil flowingin through the passage 14 comes out .along the shoulder 18 and likewiseoil returns to the outlet passage 15 along the shoulder 18. In this waythe bearings 1| are provided with lubrication. Leakage is prevented bypacking members 19 and a cap 80 which threadedly engage the right handend of the sleeve 10. Cover cap 89 covers a nut 8| by which the partsare held in assembled'relation upon the shaft 12.

The roller B is rotatably supported upon its stub shaft 56 by bearingssimilar to those provided for roller C, and the bearings for roller Bare lubricated in identical` manner, pipes 16a and 11a being providedfor inlet and outlet of lubricant. l

The feed rollers Gare made of soft rubber and are vulcanized to metalsleeves similar to roller C which is shown in longitudinal section inFig. l2. The sleeves have bearings, carried by a frame 98 having a hubjournaled in a bearing sleeve |90 carried by the frame |0|. The frame 98includes a yoke portion ||2 which joins the hub at one end while theopposite end of the bracket 98 carries a cap ||4 for closing the recesswhich receives the bearing. The lower roller G is attached to a lowershaft in the same manner as the upper roller G is attached to its shaft,and is supported upon and secured in place and properly spaced in thesame manner. Oil leaks are prevented by secured in position in the samemanner as packing members in roller C.

IThe bracket 98 may be turned upon its hub 99 in order to Vary thedistance between the upper roller G and the lower roller G as shown inFig. 4, so that the foil strip may easily be entered between the rollersor for any other reason. The bracket 98 is turned by a handle |60attached to the yoke ||2. The bracket 98 is secured in the desiredposition of adjustment by a clamp comprising a nut cooperating with ascrew provided with a handle |64. The huby |65 of the handle |64 bears`against a clamping sleeve |66. When the handle is turned so that itsscrew sesl packing members located and lill the lower feed` roll G isremoved by a scraper 500 carried by a bracket 50| pivotally supported'by a pin 502 carried Iby a lug 503 on the bracket |0I. The distancebetween' the' lower roll G and the edge of the scraper is adjusted byturning a screw 504 threaded through tapped holes in the scraper 500 andbracket 50| and bearing against lug 503. j

Referring to Figure 2, the take-up spool H is rotatably supported by ashaft 220 journaled in bearings carried by a bracket 223 fastened to aframe 20. The bracket has a flange which supports a small electric motorhaving a shaft connected with the shaft 220; The shaft 220 carries anon-conducting disc 228v having a hub surrounded by a metal ring 230having a conical surface. The outer end of the shaft 220 is threaded toreceive a nut 4232 the hub of which is surrounded by' a metal ring 233having a conical surface and insulated from the nut by a non-conductingbushing. It will be understood that the core of the take-up spool H isclamped between the conical surfaces and by screwing the nut 232 alongthe shaft 220.

The motor is a low torque series wound D. C. motor so constructed thatit may be stalled for a considerable period without damage, while thecurrent remains on. The motor tends to run at a speed which is greaterthan just necessary to keep the foil taut as it is beingwound upon the.

take-up spool H regardless of the diameter of the foil that is woundupon the'take-up spool H'.

The normal speed ofthe motor is about 215 `R. P. M., but it may operate`without injury with the speed considerably below this. It will beunderstood that the motor will turn faster when there is relatively asmall amount of foil wound upon the take-up spool H and slower as thediameter of the foil wound thereon increases.

As the foil is being wound upon the take-up spool H it is. engaged by apressure roller I which tends to iron out any `wrinkles which may bepresent in the foil and tends to pack the foil firmly upon the takeupspool H. The roller I is mountedon bearings, carried by a stub shaft26|, secured to av lever arm 262 having a hub 263 pivotally supported bya stub shaft 264 provided by a bracket 265 attached to the frame 20. Thehub 263 fis insulated from the shaft 264 by non-conducting Sleeve orlike devices, and the hub 263 is retained in place by washers 269attached to the shaft 264. The hub 263 is connected with a lever orweight rod '21| supporting a pluralityof weights 212 retained betweennuts 213 and 214. The number of these weightsvand their positions uponthe rod 21| are such as to cause theroller I to bear' with substantialpressure upon the foil., The bearings of the roller I are lubricated4 byoil 'retained within al chamber, which is sealed at one end by a plug211 screwed into the roller I. f

That part of the foil between the rollers B and Cis engaged by anon-conducting roller 280 carried by an arm28| pivoted on a shaft 282andl drop, thereby rotating the shaft 282 counterclockwise as viewed inFigures 2 and "4. I shaft 282 carries a--inercury switch which is Theconnection with Figures 1, 2, 3, 5 and 6.

for locating the partition opened by this movement of the shaft 282 allas is well known in the art. When this switch is tank J is provided witha cover 300 which supports an electric motor 30|, which drives a shaft302 carrying'at its lower end an impeller 303 located in proximity to asleeve 304 supported by partition 305 carried by the walls of the tankJ. Below the partition 305 is located a steam c oil V306 and a coldwater coil 301. In proximity to the coil 306 and 301 a pyrometer 308 islocated. This pyrometer controls devices, not shown, for regulating theadmission of steam to the coil '306, or cold water to the coil 301,dependingv upon the temperature at which the contents of the tank J isto be kept.

In this tank J is placed theliquid electrolyte used or lming. the foilF. The level of the electrolyte in the tank J is preferably at the line3|0. The electrolyte comprises preferably 13 pounds of boric acid andtwoI pounds of sodium borate to every 80 gallons of distilled water, andis maintained at a temperature just below the boiling point of water. I

The cover 300 carries oneor more rods 3||v threadedly engaging otherrods 3| 2 to which certain turns of the coils 306 and 301 are lclampedby plates 3| 3' and 3|4 and screws L3|5.

The

The rods3|2 support the partition 305. Sleeves 3|6 surround therods 3||and serve as spacers y 305 a definite distance below the cover 300. 3|1designates a sealing ring located between the flanges of the cover andtank. The weight of the motor 300 upon the tank.v

The function of thelimpeller 303 is to agitate `theelectrolyte mixturein order to keep it in a homogeneous state and in order to maintain itscirculation around thelcoils 306 and 301 and to force theelectrolyte, asindicated generally by the arrows 320, .through a pipe 32| connectedwith the bottom of the filming tank K to cause the electrolyte to risein the tank K and flow asv indicated by the arrows 322 out through'a.return pipe 323 through the upper part ofthe agitator tank J. In thisway the temperature'and the consistency of the electrolyte ismaintain'ed as uniform as possible. The level o f the elec-f trolyte lnthe lming tank K is the same as it is in the agitator tank `J.

Obviously the control ofthe temperature of the electrolyte and theagitationthereof could be effected in the tank K'by increasing its sizesufficiently to accommodate the apparatus shown in the tank J. In orderto reduce corrosion, due

maintains the lid to electrolysis, of metallic parts in contact with'.

the electrolyte, it has been found advantageous to use an agitator andtemperature control tank separate from the lming tank and toelectrically insulate both tanks from each other and fromground as faras possible. In Figure 5, numerals 30611. and 301a refer generally tothe pipe connections connected respectively `with the coils 306 and 301in the tank J. The connections 'include rubber ysections to electricallyinsulated 4 tank J from ground. The pipes 32| and 323 arenon-conducting, preferably'rubber hose. Tanks J and K are supported onnon-conducting blocks,

which are made of a suitable corrosion resisting metal or alloy, vwillnow be described. Referring to Figure I2, Ait will be seen that theframe 20 extends upwardly to provide two shelves 330 on each side of apedestal. The shelves 330 each support electrically and thermallyinsulating beams 332, which are retainedupon the shelves 330 by a plate334 screwed to the pedestal by screw 335. Beams 332 are made with asteel core around which rubber is vulcanized. A bolt 336 extends throughthe beam 332 and cooperates with a nut 331 for clamping the beams 332against thepedestal. Upon removal of the plate 334 and withdrawal of thebolt 336 the beams 332 and all the parts supported thereby may beremoved without further disassembly. The beams 332 are secured by screws338 to an electrode support 339 which is formed preferably of two"strips of corrosion resisting metal, such as Monel, channel-shaped incrossv section and welded together asfindicated at 340 in Figure 10.

A horizontal plate 3`4| is secured by screws 342 to the-upper end of theelectrode support 339, as shown in Figure 3. This plate carries an eye343 by which the electrode support 339 may be hoisted out of the tank Kafter the beams 332 of the electrodes L shape with change intemperature.

have been disconnected from the frame 20. The roller D, showndiagrammatically in Figure 1, is made of rubber and is pivotallysupported at the lower end`of the electrode support 339. For thispurpose the support 339 is provided with brackets 344 which carry pinbearings 345, preferably made of Stellite, one of which is ad- .justableby screw 346 received by bushing 341 attached to the adjacent bracket344.I

The electrode support 339 supports two pairs of electrode carriers 350of corrosion-resisting metal, such as Monel, The carriers of each pair350 are designated 35| and 352. The carriers 35| are fastened directlyIto the support .339 and the carriers 352 are hinged at 353 to thecarriers 35|. 'I'he carriers are all channel-shaped ln crossysection andthe flanges 354 of these channels are grooved at 355 to receive the sideedges which are supported by the grooves 355'inspa`ced relation to theweb 356 of each channel-shaped carrier. Each electrode L has a terminalbar LT, which extends through a notch 351, in a flange 354,thussupporting the electrode L vertically. Each pair of -flanges 354 ofeach electrode 'carrier supports a Vertical row of horizontally arrangedPyrex rods 360 which are located in adjacent pairs, as shown in Figure1, and serve to maintain the foil F at a fixed predetermined distancefrom the electrodes L. Pyrex is a preferred material for the rods 360because it is non-conducting and retains its These' rods 360 offer verylittle resistance to the passage of the foil F between them. The ange354 nearest hinge 353 is drilled throughso these rodsmay bepasseddthrough this .flange and the ends of Yfoil has been made vthatthe warping these rods remote from the hinges all rest in holes partlydrilled through the flange 354 which is remote from the hinges. The rods360 are retained in this position by a vertically extending bar-36| ofMonel metal which is retained on 5 l one side by the plates of thehinges 353. Each bar 36| has an ear 362 which rests upon the top of theadjacent channel flange 354. When the pairs of electrode carriers areseparated, as shown in Figure 7, the foil to be lmed can be 10 locatedbetween the electrodes and can be passed aroundthe rubber roller D.Thus, the foil will have two vertical runs parallel to the electrodesupport 339. After threading the foil around the electrode support thepairs of carriers 350 are l5 closed; that is, the hinged carriers 352are closed upon the fixed carriers 35| and are held in this position. t

The pairs of electrode terminals LT are se` l cured to the ends of aninverted U-shaped strap 20 310 by means of bolts 31| and nuts 312. Thestrap 310 is attached, as shown in Fig. 4, to a lead 313 whichcorresponds to the lead M in the diagram, Fig. l. The removal of theelectrodes L is facilitated by this construction. The nuts 31| are un-25 screwed from the bolts 312 to permit the disconnection of this strap310 which may then be moved out of the way since the conductor 313 isiexible. Then the operator grasps the electrodes L by their terminals LTand moves them upward- '30 ly from their respective electrode carriers.The electrodes L are removed from their carriers about once a week offive working days averaging 16 hours` each for the purpose of cleaningthe electrode surfaces. During a weeks operation of 35 the apparatus,precipitatesv from the electrcylte gather on the surface of theelectrodes L and increase the resistance to the ,ow of the filmingcurrent to such ari extent as to interfere with the normal operation ofthe apparatus. After 40 removal from the electrolyte, the electrodes Lare cleaned by scrubbing with water;

A foil filming machine constructed in accordance with the drawings andspecification has been used successfully to film aluminum foil'as thin45 as .0004 inch in thickness and at a speed of 36 of theelectrolyte andby maintaining its circulation, it is possible to use higher amperage ofcurrent than heretofore and thus accelerate the lm- 50 ing process. Thehandling of exceptionally thin possible by the use of well lubricated,anti-friction bearings of generous pro'- portions carried by a massiveframe so designed thereof due to change in tem- 55 perature visquitenegligible. In so far as possible the frame is thermally insulated'fromthe hot electrolyte. Thewater jacketing of the tank K helps to reduceheat transfer from the electrolyte to the frame. Wood blocks ,are usedto support 50 the tanks J and K uponA a base (not shown) which alsosupports the frame. The electrode support is carried by the thermallynon-conducting beams 332.

While the embodiment of the present invention as herein disclosed,constitutes a preferred form, it is to be understood that other formsbers adapted to support a cathode plate, a pair of frames hinged to thesupport and comprising channel members adapted to receive a cathodeplate, each of said frames being normally disposed on opposite-sides ofthe support and normally in closely spaced relation with the xed channelmembers, and insulating rods carried by the channel members andextending across the face of the cathode plates and defining a passagethrough which the strip material may be passed in close proximity to thecathode plates but free from engagement therewith, and an idler rollsituated at the end of the support for transposing the Imovement of thestrip material from between one pair of cathode plates to movementbetween another pair of cathode plates.

2. In an electrolyzing apparatus for lming traveling strips, thecombination comprising, a cathode support removably disposed within, butelectrically insulated from a lming tank, means carried by the supportand comprising spaced channel members adapted to support a cathodeplate, a pair of frames removably secured to the support and each havingchannel members adapted to receive a cathode plate, each 0I said framesnormally supporting a cathode plate in spaced parallel relation with acathode plate carried by the support and forming a passage through whichthe traveling strip may move, in-

sulators spaced longitudinally of the traveling strip and disposedbetween the traveling strip and each of the cathode' plates and thuspreventing contacting engagement between the contacting strip and eitherof the cathode plates.

3. In an electrolyzing apparatus for filming traveling strips, thecombination comprising, a

cathode support removably disposed within, but

electrically insulated from a lming tank, means carried by the supportand comprising spaced channel members adapted to support a cathodeplate, a pair of frames adjacent the support and comprising channelmembers adapted to receive a cathode plate, each of said frames beingnormaliy disposed on opposite sides of the support and normally inclosely spaced relation with the y fixed channel members, and insulatorscarried by the channel members and extending across the face of thecathode plates for defining a passage through which the strip` materialmay be passed in close proximity to the cathode plates, but free fromengagement therewith, there being a pair of spaced cathode plates onopposite sides of the support, and means situated at the end of thesupport for transposing the movement of the strip material from betweenone pair of cathode plates to movement between another pair of cathodeplates.

4. In a film-forming apparatus for foil strips, the combination of atank for containing electrolyte, a post of rectangular section, meanssuspending the post vertically in the tank, a pair of cathode supportingmembers carried directly by the post, a pair of cathode supportingmembers hinged to the post, and means carried by the. cathode supportsfor guiding the foil between the cathodes and for holding the foil at ailxed distance from the cathodes, a cathode support of each pair beingdisposed on opposite sides of the post, and parallel therewith.

5. In a film-forming apparatus for foil strips, in combination with atank for containing electrolyte, a rectangular post member suspendedvertically in the tank, two pairs of cathode supports, one support ofeach pair being attachedA directly to the post, means provided by saidcathode supports for guiding the foil between the cathodes and at a xeddistance from the cathode, each pair of supports being arranged inparallelism on opposite sides of the post, and a roller supported at theend of the post for engaging that portion of the lm between the pairs ofcathode supports. Y

GEORGE W. ELSEY.

